This invention relates to a flexible or floppy disk drive (which may be hereinafter called xe2x80x9cFDDxe2x80x9d for short) and, in particular, to a frame structure therefor.
In the manner which is well known in the art, the floppy disk drive of the type is a device for carrying out data recording and reproducing operation to and from a disk-shaped magnetic recording medium of a floppy disk (which may be hereinafter called xe2x80x9cFDxe2x80x9d for short) loaded therein. In addition, such a floppy disk drive is mounted or loaded in a portable electronic equipment such as a laptop personal computer, a notebook-size personal computer, a notebook-size word processor, or the like.
The floppy disk drive of the type comprises a magnetic head for reading/writing data from/to the magnetic recording medium of the floppy disk, a carriage assembly for supporting the magnetic head at a tip thereof with the magnetic head movably along a predetermined radial direction to the floppy disk, a stepping motor for moving the carriage assembly along the predetermined radial direction, and a spindle motor for rotatably driving the magnetic recording medium with the floppy disk held. The spindle motor is one of direct-drive (DD) motors.
In order to control such a floppy disk drive, an FDD control apparatus is already proposed. By way of example, Japanese Unexamined Patent Publication Tokkai No. Hei 9-97,493 or JP-A 9-97493 discloses, as the FDD control apparatus, one integrated circuit (IC) chip which incorporates first through third control circuits therein. The first control circuit is a reading/writing (hereinafter called xe2x80x9cR/Wxe2x80x9d) control circuit for controlling reading/writing of data. The second control circuit is a stepping motor (hereinafter called xe2x80x9cSTPxe2x80x9d) control circuit for controlling drive of the stepping motor. The third control circuit is a general controlling (hereinafter called xe2x80x9cCTLxe2x80x9d) control circuit for controlling whole operation of the flexible disk drive. The CTL control circuit may be called a logic circuit. This IC chip is generally implemented by a metal oxide semiconductor (MOS) IC chip where a number of MOS field effect transistors (FETs) are integrated therein.
The FDD control apparatus comprises not only the one IC chip but also a spindle motor IC chip for controlling drive of the spindle motor. The spindle motor IC chip is implemented by a bipolar IC chip where a number of bipolar transistors are integrated therein.
Now, floppy disk drives have different specifications due to customers or users. The specification defines, for example, drive select 0 or 1, the presence or absence of a special seek function, the presence or absence of an automatic chucking function, a difference of logic for a density out signal, a difference of logic for a mode select signal, 1M mode 250 kbps or 300 kbps, and so on. If development is made of one IC chips which individually satisfy the different specification, a number types of one IC chips must be prepared. In order to avoid this, a one IC chip having a selectable function circuit is already proposed, for example, in Japanese Unexamined Patent Publication Tokkai No. Hei 9-97,839 or JP-A 9-97839 wherein all functions satisfying all specifications are preliminarily incorporated therein and one of the functions is selected in accordance with a particular specification.
In the manner which is well known in the art, the floppy disk driven by the floppy disk drive includes a disk-shaped magnetic recording medium accessed by the magnetic head. The magnetic recording medium has a plurality of tracks on a surface thereof that serve as paths for recording data and that are formed in a concentric circle along a radial direction. The floppy disk has eighty tracks on one side which include the most outer circumference track (which is named xe2x80x9cTR00xe2x80x9d) and the most inner circumference track (which is named xe2x80x9cTR79xe2x80x9d). The most outer circumference track TR00 is herein called the most end track.
It is necessary to position the magnetic head at a desired track position in a case where the floppy disk is accessed by the magnetic head in the floppy disk drive. For this purpose, the carriage assembly for supporting the magnetic head at the tip thereof must be positioned. Inasmuch as the stepping motor is used as a driving arrangement for driving the carriage assembly, it is possible for the floppy disk drive to easily carry out the positioning of the carriage assembly. In spite of this, it is necessary for the floppy disk drive to detect only the position of the most end track TR00 in the magnetic recording medium of the floppy disk loaded therein. In order to detect the position of the most end track TR00, the carriage assembly is provided with an interception plate which projects from a base section thereof downwards and a photointerrupter is mounted on a substrate in the vicinity of a main frame opposed to the carriage assembly. For example, see Japanese Unexamined Patent Publication Tokkai No. Hei 9-91,859 or JP-A 9-91859. That is, it is possible to detect that the magnetic head is laid in the position of the most end track TR00 in the magnetic recording medium of the floppy disk because the interception plate intercepts an optical path in the photointerrupter. Such a track position detecting mechanism is called a xe2x80x9c00 sensorxe2x80x9d in the art.
In prior art, a magnetic sensor (rotor position detector) is used in order to control the spindle motor and Hall elements are generally used as detecting elements for use in the magnetic sensor. In other words, a conventional magnetic sensor comprises a plurality of Hall elements. The spindle motor using such as Hall elements is called a xe2x80x9cHall motor.xe2x80x9d In the manner which is known in the art, the xe2x80x9cHall elementxe2x80x9d is a semiconductor element applying a xe2x80x9cHall effectxe2x80x9d which is a phenomenon where an electromotive force occurs in a direction perpendicular to each of a current and a magnetic field when the magnetic field is applied to the current flowing a conductor in a direction perpendicular to a direction of the current. A voltage generated by each Hall element is called a Hall voltage. That is, the Hall element is an element for converting strength of a magnetic field into a voltage.
In the manner which will later be described in conjunction with FIGS. 7 through 9, a conventional floppy disk drive comprise not only a main frame but also a motor frame for mounting the DD motor (spindle motor) thereon. In other words, the motor frame is constituted as another piece different from the main frame. In addition, the main frame is also called a main chassis while the motor frame is also called a motor base. Accordingly, the conventional floppy disk drive is disadvantageous in that it requires a lot of parts and the number of processes for assembling increases. In addition, the conventional floppy disk drive is also disadvantageous in that a characteristic of the spindle motor (DD motor) is dispersed on mounting the motor frame on the main frame and it is therefore difficult to stabilize the spindle motor.
It is therefore an object of the present invention to provide a floppy disk drive which is capable of reducing the number of parts.
It is another object of the present invention to provide a floppy disk drive of the type described, which is capable of decreasing the number of processes for assembling.
It is still another object of the present invention to provide a floppy disk drive of the type described, which is capable of suppressing dispersion in a characteristic of a spindle motor mounted therein to stabilize the spindle motor.
Other objects of this invention will become clear as the description proceeds.
On describing the gist of an aspect of this invention, it is possible to be understood that a floppy disk drive comprises a main frame in which a floppy disk is inserted and a motor for rotatably driving the floppy disk inserted in the main frame. According to the aspect of this invention, the above-understood floppy disk drive comprises a motor frame part for mounting the motor thereon that is constituted by one piece integrated by the main frame.
On describing the gist of another aspect of this invention, it is possible to be understood that a frame structure is for use in a floppy disk drive for driving a floppy disk inserted therein. According to the other aspect of this invention, the above-understood frame structure comprises a main frame in which the floppy disk is inserted and a motor frame part for mounting a motor for rotatably driving the floppy disk inserted in the main frame. The main frame and the motor frame part constitute one piece in which the main frame and the motor frame part are integrated.
In the above-mentioned floppy disk drive or in the above-mentioned frame structure, the motor frame part may have a drawn-shape obtained by drawing the main frame. In the above-mentioned floppy disk drive comprises an electronic processing arrangement for a frequency generation pattern. The electronic processing arrangement gives play to a function equivalent to the frequency generation pattern required to control the motor.